Occurrence Of Aphids Research Articles

Population fluctuation and faunal indices of aphids (Hemiptera, Aphididae) in peach orchards in Araucária, PR

Aphids are sap-sucking insects that mainly attack shoots and young leaves of peach trees and many other plant species; however, knowledge of the Brazilian aphid fauna is scant. The objective of this study was to identify aphid species collected in peach orchards (Prunus persica Batsch) and to determine their faunal indices for occurrence and dominance. The experiment was conducted from July 2005 to September 2006 in six Chimarrita peach orchards in the municipality of Araucária, PR, Brazil. The survey of aphid species was conducted by visual samplings on peach trees and using Möericke-type yellow traps containing water. A faunal analysis was made using aphid occurrence and dominance indices. Brachycaudus persicae (Passerini, 1860) was the only aphid species that was found colonizing peach in Araucária/PR. Although most aphids collected were classified as rare, some can be considered potential peach colonizers, such as Myzus persicae (Sulzer, 1776) which was given the status of common or intermediate in some of the orchards studied. The population fluctuation of aphids showed a negative correlation with rainfall and positive correlation with temperature and relative humidity.

Heteropterans as aphid predators in inter-mountain alfalfa

The relationships between predatory Heteroptera and their potential prey species were investigated during two crop seasons in an inter-mountain area close to the Pyrenees (Iberian Peninsula). Regression was used to analyze the potential numerical responses shown by heteropterans to aphids and other potential prey during alfalfa intercuts (the plant growth period between cuts) of high aphid occurrence. The most abundant heteropterans were Orius spp., Nabis spp. and mirids, and all were present in alfalfa stands throughout the season. Acyrthosiphon pisum was the prevalent species during the 2nd intercut, Therioaphis trifolii during the 4th and Aphis craccivora during the 5th. We performed simple regression analysis between the Orius sp., Nabis sp. and mirids and the prevalent aphid species, forward multiple regression analysis between heteropterans and all possible soft-bodied prey species; and both analyses for coccinellids, as relative aphid predator specialists. The heteropterans responded numerically to A. pisum but not to T. trifolii or A. craccivora. Heteropterans also showed numerical responses to other potential prey (leafhoppers, thrips, and other soft bodied prey) that remained at low densities throughout the season. All these preys may contribute to the presence of heteropterans in alfalfa stands throughout the season. The results suggest that heteropterans may contribute to reduce A. pisum, particularly at the beginning of the growing season, and on other potential pests when they invade or recolonize alfalfa, and may help to delay or prevent the build-up of these pest populations.

Trends in Aphid Occurrence in Spring Barley in 1976-2007

Recently, considerable attention has been paid to climate change effects on nature and abundance of pests affecting agricultural crops. Our study was focused on the trends in aphid abun- dance during the growing seasons in spring barley in 1976-2007. Analysis was conducted based on the records of aphid abundance observations and detailed meteorological data. The first step in the study was to clarify the effects of temperature on aphid occurrence and abun- dance in spring barley. This part of the study was restricted to Dotnuva site, which is a typical area for commercial crop production, in order to reduce the influence of such effects as management, macroclimate, soil and others. A distinct and statistically significant increase in the mean air temperature was noted at the experi- mental site of the Lithuanian Institute of Agriculture in Dotnuva, Kedainiai for the period 1976-2007. A statically significant positive trend was identified for the mean air temperature during April-No- vember. Consequently, during the last decade the occurrence of aphids has also become quite fre- quent.

Influence of Plant population and Use of Insecticides on the Sugarcane Aphid Occurrence, Melanaphis sacchari (ZEHNTER), in Sorghum

Influence of Plant population and Use of Insecticides on the Sugarcane Aphid Occurrence, Melanaphis sacchari (ZEHNTER), in Sorghum

Occurrence of Aphids on West Indian Cherry Malpighia emarginata in Miyagi Prefecture

Occurrence of Aphids on West Indian Cherry <I>Malpighia emarginata</I> in Miyagi Prefecture

Ocorrência e flutuação populacional de tripes, pulgões e inimigos naturais em crisântemo de corte em casa de vegetação

Os pulgões e os tripes são importantes pragas em cultivo de crisântemo em casas de vegetação. O objetivo deste trabalho foi avaliar a ocorrência e flutuação populacional de tripes, pulgões e inimigos naturais em cultivares de crisântemo de corte ('White Reagan', 'Yellow Snowdon' e 'Sunny Reagan') em casa de vegetação comercial. A amostragem de tripes foi realizada através de batidas nas plantas ("tapping method") e a de pulgões a partir de coletas diretas nas plantas. Das espécies de tripes amostradas, mais de 90% foram identificadas como Frankliniella occidentalis (Pergande), e o restante incluíram F. gemina (Bagnall), Frankliniella sp., Caliothrips phaseoli (Hood) e Haplothrips gowdeyi (Franklin). Foi observado maior número de tripes/planta no cultivar White Reagan se comparado com 'Yellow Snowdon'. Aphis gossypii Glover foi a espécie de pulgão mais comum (&gt; 80%), sendo também coletados Myzus persicae (Sulzer) e Dysaphis sp. Maior número de pulgões foi verificado na cultivar White Reagan, quando comparada com 'Sunny Reagan'. Orius insidiosus (Say) foi o único predador encontrado associado aos tripes, sendo verificada uma correlação positiva significativa entre a população de tripes e a desse predador. Dentre os inimigos naturais relacionados aos pulgões, foram observados parasitóides (Aphidius colemani Viereck e Lysiphlebus testaceipes Cresson) e predadores (Chrysoperla sp., Cycloneda sanguinea Linnaeus e Scymnus sp.). Houve uma correlação positiva significativa entre o crescimento populacional de pulgões e desses predadores e parasitóides nas cultivares White Reagan e Sunny Reagan. Inimigos naturais podem ocorrer naturalmente em casas de vegetação e influenciar as populações de pragas.

Short Communication: Occurrence of the pea aphid, &lt;i&gt;Acyrthosiphon pisum&lt;/i&gt; (Harris) (Homoptera: Aphididae) on wild leguminous plants in West Gojam, Ethiopia

The occurrence of pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on wild annual and perennial leguminous plants was studied at two locations (Adet and Wondata) in West Gojam, Ethiopia in 1999/2000 seasons. Annual and perennial leguminous wild or volunteer plants encountered in the study areas were closely monitored for the presence of pea aphid. The results showed that pea aphids infested annual legumes such as clover ( Trifolium ruepellainum ) (wild) and vetch ( Vicia spp) carried more aphid load than clover. The aphid attacked more vetch in September and clover in October. From perennial legumes, pigeon pea ( Cajanus cajan ) was the most susceptible to attack by pea aphids and it was heavily infested and damaged in September and October. High plant density of vetch carried more aphid load than low plant density; sole stand of vetch plants suffered more damage than when grown mixed up with other crops or weeds suggesting the advantage of intercropping to reduce pea aphids. Key words/phrases: Acyrthosiphon pisum, Ethiopia, leguminous plants, pea aphid, wild hosts SINET: Ethiop. J. Sci Vol.26(1) 2003: 83-87

Effects of climate and land use on the occurrence of viruliferous aphids and the epidemiology of barley yellow dwarf disease

Abstract Barley yellow dwarf (BYD) disease is one of the most severe viral diseases in autumn sown cereals. In Western Europe, crop losses are mainly due to the PAV species of BYD viruses transmitted by Rhopalosiphum padi , the most abundant aphid in autumn. The proportion of migrant winged aphids that carry viruses in autumn is considered a major epidemiological factor for determining the disease incidence. In the main French cereal areas, during a 6-week period in autumn 1999–2002, the proportion of viruliferous R. padi assessed using a TAS-ELISA technique was on average of 4.98% (range 2.01–9.91%). Variations according to trap location were correlated with land use at the regional scale, annual variations being correlated with the climate of the year. Implementations of these results to improve BYD disease management program are discussed.

Relative Occurrence and Abundance of Mustard Aphid, Lipaphis erysimi (Kalt.) and Their Predators on Rainbow and Oscar Canola Varieties

The studies on the relative occurrence and abundance of mustard aphid, Lipaphis erysimi (Kalt.) revealed that aphid appeared on leaves during 3rd week of January and on the inflorescences during 2nd week of February and continued up to harvesting on both the varieties. The peak populations (42.7) and (28.7) per leaf on Rainbow and Oscar varieties were recorded. Whereas, the peak populations (7.5) and (6.6) per inflorescences were recorded on these varieties. The higher mean population ranges (9.2 to 28.7) and (25.1 to 42.7) per leaf on Oscar and Rainbow and (3.9 to 6.6) and (2.3 to 7.6) per inflorescence were recorded from February 15 to March 5. The temperature range of 16.5 to 20.6 °C, seems to have favored the pest multiplication. The predator species such as, green lacewing beetle, Chrysoperla cornea (Stephens), eleven-spotted ladybird beetle, Coccinella undecimpunctata (Linn.) and seven-spotted ladybird beetle, Coccinella septempunctata (Linn.) were recorded when the pest population of aphids was sufficiently developed on the canola varieties.

Occurrence and parasitism of aphids (Hemiptera: Aphididae) on cultivars of irrigated oat (Avena spp.) in São Carlos, Brazil

The interactions between aphids and their Hymenopteran parasitoids on irrigated oats as well as the response of different cultivars of cereals regarding the resistance to these aphids and the influence on the host/parasitoid relationships were studied during two years in São Carlos, Brazil. Rhopalosiphum padi (L.) was the predominant aphid observed throughout the study, while the other species were rarely found. Five species of parasitic Hymenoptera were found: three primary parasitoids, Lysiphlebus testaceipes (Cresson), Aphidius colemani (Viereck) and Diaeretiella rapae (M'Intosh) and two hyperparasitoids, Syrphophagus aphidivorus (Myer) and Alloxysta brassicae (Ashmead). The UPF 86081 cultivar presented significant results regarding lower Rhopalosiphum padi contamination and higher aphid parasitism rates than those observed on some other cultivars. No significant effect on the percentage variation of parasitoid emergence on the mummified aphids was observed throughout this study.

Ocorrência de afídeos em alface (Lactuca sativa L.) em cultivo hidropônico

A ocorrência de afideos foi avaliada em alface cultivada hidroponicamente na área de produção da Escola Agrotécnica da Universidade Estadual de São Paulo (UNESP), em Jaboticabal, São Paulo, de janeiro a dezembro de 1999. Foi constatado que o número total de cada espécie de afideo, presentes em amostragens conduzidas semanalmente durante o período, foi correlacionada com a média de temperaturas registradas dentro do período de amostragem. Foi registrada a ocorrência de três espécies de afideos, Uroleucon ambrosiae (Thomas), Myzus persicae (Sulzer) e Macrosiphum euphorbiae (Thomas), sendo as maiores densidades populacionais coincidentes com médias de temperaturas inferiores a 21,5°C. As maiores densidades populacionais de U. ambrosiae ocorreram de maio a junho. Na segunda semana de maio e na terceira semana de novembro foram registrados dois picos populacionais máximos de M. persicae. A espécie M. euphorbiae predominou sobre as demais e as maiores populações dessa espécie foram observadas nos períodos de maio a junho e final de julho a início se setembro. Foi constatada correlação negativa entre populações de afideos e temperatura. Esta correlação, entretanto, foi estatisticamente significativa somente para M. euphorbiae e U. ambrosiae.

Controlled atmospheres for the post-harvest control of Myzus persicae (Sulzer) (Homoptera: Aphididae): effects of carbon dioxide concentration

Abstract Green peach aphids, Myzus persicae (Sulzer) were exposed to 15 CO 2 concentrations from 0% to 95%, all with 5% oxygen, at 12°C for 40 h. Initial survival was assessed 2 days post-treatment, and then for up to 12 days for moribund insects. The aim was to determine the relationship between aphid mortality and CO 2 concentration. At CO 2 concentrations between 20% and 60%, 30% of the treated aphids were moribund 2 days after treatment but all moribund aphids died within the next 10 days. Models were fitted to the dose–response curves arising from the relationship of mortality to CO 2 concentration. Two days after treatment the mortality curve deviated significantly from a standard dose–response curve partly because of the occurrence of moribund aphids. Above 40% CO 2 , mortality was over 90% 12 days after treatment indicating the presence of a physiological threshold at that point. The occurrence of significant numbers of moribund aphids poses challenges to standard quarantine inspections as the aphids respond to stimulation as though they are alive, despite the fact they will all die within 12 days. To develop quarantine treatments for perishable commodities such as lettuce and asparagus from data such as those presented here requires further research, including optimising temperature and exposure time for both pest mortality and crop quality.

Abundance of cereal aphids (Hemiptera: Aphididae) within wild Triticum and Aegi­lops spp., and cultivated wheat

Accessions of the wild Triticum species: T. boeticum, T. dicoccoides, T. urartu, and the Aegilops species: Ae. columnaris, Ae. geniculata, Ae. markgrafii, Ae. neglecta and Ae. triuncialis in the collection of the Gene Bank of RICP Prague-Ruzyně, with T. aestivum cv. Sandra as control, were evaluated for cereal aphid occurrence in the open during 1995–1998 period. The cereal aphid species Rhopalosiphum padi (RP), Metopolophium dirhodum (MD) and Sitobion avenae (SA) were predominant on the plants. Variations in the abundance of individual aphid species in each year were found. The results from 1997, the optimal year for aphid occurrence, showed differences between both aphid and plant species. RP significantly dominated in Triticum species, while SA preferred Aegilops accessions. A significant negative correlation was found between RP and MD densities in the Triti­ cum spp., while MD and SA occurrence showed a negative relation to that of RP and SA in the Aegilops accessions. The individual aphid species showed a similar pattern of infestation in several genomically close accessions.

Simulation of counts of aphids over two hectares of Brussels sprout plants

Abstract Populations of the mealy cabbage aphid, Brevicoryne brassicae (L.), on Brussels sprout plants, Brassica oleracea (L.) were sampled, fortnightly throughout the early season of 1996, in 2 ha 2 blocks. Sampling was done on two spatial scales, firstly over 25, 5×5 m sample areas, and then on the 20 plants within each of these areas. On each occasion, the occurrence of aphids was recorded on all the 500 plants sampled per block (one in 16 plants) and the count of the number of aphids per plant measured on a selected five plants per area, yielding information from 125 plants per block (one in 64 plants). The data were analysed to study various aspects of the aphids’ frequency distribution at each of the two scales, particularly the relationship between variability and population density, and the relationship between the proportion of plants infested and density. Patterns of the incidence of infestation differed radically between the two blocks. Also, for a given aphid density, more plants were infested as the season progressed, and at that density there were therefore, on average, fewer aphids per plant at later dates. Methodology was outlined to simulate realistic aphid counts, conforming to the relationships found for each of the two scales around the time of the achievement of a threshold incidence of 10% infestation. This was used to generate a count for each of the 8000 plants per block, for each of the blocks, representing a 64-fold increase in information. It was verified that these simulations provided realistic sets of counts, that could be used subsequently to study the efficiency of aphid sampling schemes and to replace costly extensive surveys for the development of control strategies.

SEASONAL INCIDENCE AND MANAGEMENT OF APHID, Aphis punicae on POMEGRANATE

The maximum incidence of aphid, Aphis punicae was observed on pomegranate during the third week of February and March respectively in hill area at Yercaud and plains at Namakkal in Tamil Nadu. Both grubs and adults of the predatory coccinellid beetle. Scymnus coccivora were highly effective in reducing the population of aphids. A grub could feed on an average of 423 nymphs or 216 adults of aphids during the entire grub period. Inundative release of the green lace wing. Chrysoperla carnea @ 50 first instar nymphs per flowering branch four times at 10 days interval. coinciding the first release on the occurrence of aphids, resulted in 53.67 per cent reduction in aphid population. Among the chemicals, spraying of neem oil 3%, fish oil rosin soap 2.5%, phosalone and endosulfan at 0.07%, dimethoate and phosphamidon at 0.03% and methyl demeton 0.025% were highly effective in controlling the aphid population.

Ocorrência e flutuação populacional de predadores e parasitóides de Brachycaudus (Appelia) schwartzi (Börner) (Homoptera: Aphididae), em Pessegueiro, em Jacuí, MG

Estudou-se a ocorrência e a flutuação populacional dos inimigos naturais (predadores e parasitóides), associados ao pulgão Brachycaudus schwartzi (Börner), em pessegueiro (Prunus persica). Foram amostrados quinzenalmente de agosto de 1994 a julho de 1995, dois ramos de aproximadamente 25 cm por planta em 10 plantas. No laborátório, foi realizada a triagem e contagem dos pulgões e de seus inimigos naturais. Constatou-se a presença de predadores das famílias Coccinellidae (seis espécies) e Syrphidae (sete espécies) e também do parasitóide Aphidius colemani Viereck (Aphidiidae). Os predadores foram mais abundantes de agosto a dezembro de 1994, coincidindo com a maior ocorrência do pulgão B. schwartzi. Dentre as espécies de coccinelídeos amostradas, a espécie Scymnus (Pullus) argentinicus (Weise) destacou-se, correspondendo a 43,9% do total de coccinelídeos amostrados. Os coccinelídeos apresentaram o pico populacional no mês de outubro. A espécie Allograpta neotropica Curran (Syrphidae) foi a de maior ocorrência, com maior pico em setembro, correpondendo a 86,7% dos sirfídeos amostrados. O pico populacional de A. colemani significativo também ocorreu no mês de setembro.

Effect of the Harvesting Time on the Occurrence of Aphids in the Spring Alfalfa Field

Effect of the Harvesting Time on the Occurrence of Aphids in the Spring Alfalfa Field

Relationship between aphid occurrence and spread of potato virus Y° (PVY°) in field experiments in southern Sweden

AbstractField experiments were carried out in potato fields in 1975–1979 to study the natural spread of potato virus Y° from diseased potato plants (virus sources) to progeny tubers of adjacent healthy potato plants. The occurrence of alate aphids was studied by using yellow water traps (YWT) and the aphid population on the potato foliage was estimated by counting aphids on 100 randomly chosen leaves. There was a good correlation between the number of alate aphids trapped in YWT and spread of potato virus Y°. Rhopalosiphum padi were probably the main vector, but many other aphid species could also have contributed, e.g. Aphis fabae, A. nasturtii, A. frangulae, Phorodon humili and Hyperomyzus lactucae. There were only weak association between numbers of apterae on potato leaves and the spread of PVY°.ZusammenfassungFreilanduntersuchungen zur Beziehung zwischen dem Aphidenauftreten und der Ausbreitung des Kartoffelvirus (PVY°) in SüdschwedenIn den Jahren 1975 bis 1979 wurden auf Kartoffelfeldern Versuche durchgeführt, um die natürliche Ausbreitung des Kartoffelvirus Y° von erkrankten Pflanzen (Virusquelle) auf die Knollen gesunder Kartoffelpflanzen zu untersuchen. Das Vorkommen von Läusen (Alatae) wurde mittels gelber Wasserfallen festgestellt, die Läusedichte auf den Kartoffelfeldern wurde geschätzt, indem die Läuse auf 100, zufällig ausgewählten Blättern gezählt wurden. Es bestand eine gute Korrelation zwischen der Anzahl der auf den Feldern gefangenen Läuse und der Verbreitung des Virus. Rhopalosiphum padi war vermutlich der Hauptvektor, aber auch eine ganze Reihe anderer Arten, wie Aphis fabae, A. nasturtii, A. frangulae, Phorodon humili und Hyperomyzus lactuae, könnten an der Virusübertragung beteiligt gewesen sein. Zwischen der Anzahl der Apteren auf den Blättern und der Verbreitung des Y°‐ Kartoffelvirus bestand nur eine geringe Korrelation.

Aphid migration and the importance of some aphid species as vectors of potato virus Yo (PVYo) in Sweden

The relationship between the occurrence of alate aphids and the proportion of progeny tubers infected by potato virus Yo (PVYo) was studied in 7 regions of Sweden from 1976 until 1984. The importance of mature-plant resistance and the proportion of PVYo diseased potato source plants were also considered.

The infection pressure of potato virus Yo and the occurrence of winged aphids in potato fields in Sweden

Water-filled yellow trays sited in a potato field were used to catch different species of winged aphids. The catches, enumerated weekly, were compared with the spread of potato virus Yo (PVYo), detected by bait plants of tobacco and potato, during the growing season for four years.